Process of making sulfuric anhydrid.



UNITED STATES PATEHIM-QJEEI'QE.

HENRY SPENCER BLAOKMORE, OF MULJNL' VERNON, NEW YORK.

PROCESS OF MAKING SULFURIC ANHYDRID.

SPECIFICATION forming part of Letters Patent No. 686,022, dated November 5, 1901.

Application filed February 16, 1900- Serial No. 5,513. (No specimens.)

T aZZ whom it may concern:

Be itknown that I, HENRY SPENCER BLACK MORE, a citizen of the United States, residing at Mount Vernon, in the county of Westchester and State of New York, have invented certain new and useful Improvemen ts in Processes of Producing Sulfuric Anhydrid and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to a which it appertains to make and use the same.

The object of myinvention is to produce sulfuric anhydrid (sulfur trioxid and it consists in oxidizing sulfur dioxid by action of a metallic oxid or substances containing the same.

It is well known that certain metalssuch as iron, copper, &c'.-have a variableaiiinity for oxygen, according to the temperature at which maintained. For example, steam passed over iron at white heat is decomposed, producing iron oxid and hydrogen gas, while if the temperature of the iron oxid thus proconducted sulfur dioxid over iron oxid at low temperatures-4'. e. below the dissociatingpoint of sulfur trioxid and found that it has the property of absorbing the oxygen therefrom, reducing the iron oxid and producing sulfur trioxid, which distils or sublimes and is finally condensed.

The reaction which takes place maybe illustrated by the following chemical formula or equation: Employing ferric oxid- It is obvious that the temperature must not be maintained above the dissociatingpoint of sulfur trioxid; otherwise it would preclude its formation. y t

The manner in which I proceed to carry out my process on a commercial scale is to place in a retort or container iron oxid and temporarily heat the same slightlysay about 212 Fahrenheittc start the operation, then conveying over or through the said iron oxid sul fur dioxid, which has preferably been heated, so that thereafter the reaction may be maintained by the occluded heat of the sulfur dioxid, and thus avoiding the application of directly-applied heat as much as possible,which is hard to regulate and keep below the dissociating-point of the sulfur trioxid produced. The heated sulfur dioxid passed over the metallic oxid in ordinary cases sufficiently heats the same after starting the operation to assure the reaction continuously until the iron oxid is reduced; also, considerable heat is liberated by the oxidation of the sulfur dioxid in direct contact with the metallic oxid, so that the reaction is practically maintained after the first heating, which merely serves to start the operation, by the combined heat of that occluded by the introduced sulfur dioxid and that liberated during reaction. The sulfur trioxid produced is distilled or sublimed and finally condensed The iron reduced by oxidation of the sulfur dioxid is then reoxidized by simply elevating the temperature and passing air or oxygen over the same, so that the oxidizing agent (metallic oxid) is regenerated and reused over and over again without loss, thus rendering the proc ess practically continuous.

It is obvious that other metals, such as copper, may be employed without departing from the spirit of my invention, which consists in oxidizing sulfur dioxid by the action of metallic oxid.

If metallic oxid heats too rapidly during reaction, it may be refrigerated to keep below dissociating-point of sulfuric anhydrid.

When cupric oxid is employed, the reac tion may be illustrated by the following chemical formula or equation:

The term metallic oxid or iron oxid as herein employed is intended to include any substance containing a metallic oxid which will give up its oxygen to oxidize sulfur dioxid to sulfur trioxid under the conditions described as well as the pure metallic oxid per 36.

Having now described my invention-,what

I claim as new, and desire to secure by Letters Patent, is' i l. The process of producing sulfuric anhydrid (S0 which consists in oxidizing sulfur dioxid by the action of metallic oxid.

2. The process of producing sulfuric anhydrid, which consists in conveying sulfur dioxid in contact with metallic oxid at a temperature below the dissociating-point of sulfur trioxid.

3. The process of producing sulfuric anhydrid, which consists in exposing a metallic oxid to the action of heated sulfur dioxid.

4. The continuous process of producing sulfuric anhydrid (S0 which consists in exposmg metallic oxid to the action of sulfur dioxid at a temperature below the dissociatingpoint of sulfur trioxid, conveying the sulfur trioxid produced to a condenser, elevating the temperature of the metallic residue, passing oxygen over the same, cooling, exposing Witnesses:

H. N. JENKINS, WARREN O. STONE. 

